Comparative performance of UK mutual building societies and stock retail banks: further evidence: a comment

Abstract:
Shiwakoti et al. (2008) concluded that four of the largest UK mutual societies which converted to listed bank status in 1997 outperformed, on a variety of measures, those societies which did not convert in the four-year periods both before and after conversion. All four converting societies have since been subject to ownership change, suggesting that this out-performance failed to persist, or was perhaps illusory. We do not criticise the results obtained by the authors, but suggest that they leave unanswered important questions, such as how to measure ‘superior’ performance and the appropriate time frame over which to evaluate this.